Minimally invasive surgery is a surgical approach aimed at reducing the healing time and trauma to a patient as a result of performing surgery on internal organs. In this approach, the treated internal organs are accessed through a small number of incisions in the patient's body. In particular, cannulas or sleeves are inserted through small incisions to provide entry ports through which surgical instruments are passed. Alternatively, access to the area to be treated is obtained using a natural bodily opening (e.g., throat, rectum), a cannula or sleeve is inserted into the bodily opening and the surgical instruments are passed through the cannula/sleeve or the bodily opening and the operable end localized to the treatment site.
The surgical instruments are generally similar to those used in open surgical procedures except they include an extension (e.g., a tubular extension) between the end of the tool entering the surgical field (i.e., the operable end of the tool, instrument or device) and the portion gripped by the surgeon. Because the surgical site or treatment site is not directly visible to the surgeon or other medical personnel when performing a minimally invasive procedure, a visualization tool/guide (e.g., endoscope, laparoscope, laryngoscope, etc.) also is inserted along with the surgical instruments so that, as the surgeon manipulates the surgical instruments outside of the surgical site, he or she is able to view the procedure on a monitor.
The limited motion available at the operable end of current devices, however, creates limitations that necessarily limit that which can be accomplished with the methods and procedures using current devices and systems. Most instruments or devices are rigid and are limited to motions of four (4) degrees of freedom of motion or less about the incision point and in/out translation. Further, the instruments can limit the surgeon's ability to accurately perceive the force/interaction between the instruments and tissues/organs. Some techniques have been established whereby the location of the incision(s) is optimized so as to in effect counter the limitations imposed by the available movement of a given instrument. This approach, however, does not work for all surgical techniques such as those surgical techniques in which access to the treatment or surgical site is accomplished using an existing bodily opening, such as the throat.
Several approaches to distal tool dexterity enhancement have been reported including designs for catheters or surgical tool manipulation devices based on articulated designs. Many systems and actuation methods are mainly based on wire actuation or use of wire actuated articulated wrists [G. Guthart and K. Salisbury, “The Intuitive' Telesurgery System: Overview and Application,” IEEE International Conference on Robotics and Automation, pp. 618-621, 2000; M. Cavusoglu, I. Villanueva, and F. Tendick, “Workspace Analysis of Robotics Manipulators for a Teleoperated Suturing Task,” IEEE/RSJ International Conference on Intelligent Robots and Systems, Maui, Hi., 2001] and by using Shape Memory Alloys (, bending SMA forceps were suggested for laparoscopic surgery, Y. Nakamura, A. Matsui, T. Saito, and K. Yoshimoto, “Shape-Memory-Alloy Active Forceps for Laparoscopic Surgery,” IEEE International Conference on Robotics and Automation, pp. 2320-2327, 1995]; an SMA actuated 1 degree of freedom planar bending snake device for knee arthroscopy was described, P. Dario, C. Paggetti, N. Troisfontaine, E. Papa, T. Ciucci, M. C. Carrozza, and M. Marcacci, “A Miniature Steerable End-Effector for Application in an Integrated System for Computer-Assisted Arthroscopy,” IEEE International Conference on Robotics and Automation, pp. 1573-1579, 1997; and a hyper-redundant SMA actuated snake for gastro-intestinal intervention was described; [D. Reynaerts, J. Peirs, and H. Van Brussel, “Shape Memory Micro-Actuation for a Gastro-Intesteinal Intervention System,” Sensors and Actuators, vol. 77, pp. 157-166, 1999). A two DoF 5 mm diameter wire-driven snake-like tool using super-elastic NiTi flexure joints also has been described [J. Piers, D. Reynaerts, H. Van Brussel, G. De Gersem, and H. T. Tang, “Design of an Advanced Tool Guiding System for Robotic Surgery,” IEEE International Conference on Robotics and Automation, pp. 2651-2656, 2003]. Also described is actuation methods and systems that use Electro-Active Polymers (EAP) (e.g., see A. Della Santa, D. Mazzoldi, and DeRossi, “Steerable Microcatheters Actuated by Embedded Conducting Polymer Structures,” Journal of Intelligent Material Systems and Structures, vol. 7, pp. 292-300, 1996). These designs however, have a number of limitations. The articulated designs limit downsize scalability and complicate the sterilization process and wire actuation limits the force application capability since the wires can apply only pulling forces (i.e., buckle when pushed). SMA suffers from hysteresis and low operation frequency due to the time necessary for temperature changes to affect its martensite/austenite change. Also, the various designs of catheters do not meet the force application capabilities required for surgical tool manipulation.
Other approaches have been reported describing snake robots using a flexible backbone for snake-like robots (e.g., see I. Gravagne and I. Walker, “On the Kinematics of Remotely-Actuated Continuum Robots,” IEEE International Conference on Robotics and Automation, pp. 2544-2550, 2000; I. Gravagne and I. Walker, “Kinematic Transformations for Remotely-Actuated Planar Continuum Robots,” IEEE International Conference on Robotics and Automation, pp. 19-26, 2000; C. Li and C. Rhan, “Design of Continuous Backbone, Cable-Driven Robots,” ASME Journal of Mechanical Design, vol. 124, pp. 265-271, 2002; G. Robinson and J. Davies, “Continuum Robots—a State of the Art,” IEEE International Conference on Robotics and Automation, pp. 2849-2853, 1999). These efforts, however, focused on large scale snake-like robots that used one flexible backbone actuated by wires (see S. Hirose, Biologically Inspired Robots, Snake-Like Locomotors and Manipulators: Oxford University Press, 1993). Also, these designs have a number of limitations including that wire actuation in only a pull mode does not allow for large force actuation once the diameter of the snake is downsized to diameters less than 5 mm. Further, when the diameter of the snake like unit is downsized, the stiffness of the snake-like unit is relatively low because it relies only on one central backbone supported by wires. This is strongly seen in the tensional stiffness.
Alternative designs of a 3 DoF wrist for MIS suturing were analyzed and a method was proposed to determine the workspace and to optimize the position of the entry port in the patient's body to provide optimal dexterity [M. Cavusoglu, I. Villanueva, and F. Tendick, “Workspace Analysis of Robotics Manipulators for a Teleoperated Suturing Task,” IEEE/RSJ International Conference on Intelligent Robots and Systems, Maui, Hi., 2001]. Also, three architectures of endoscopic wrists: a simple wire actuated joint, a multi-revolute joint wrist, a tendon snake-like wrist; have been analyzed and these joints compared in terms of dexterity and showed the superiority of the snake-like wrist over the other two wrists in terms of dexterity [A. Faraz and S. Payandeh, “Synthesis and Workspace Study of Endoscopic Extenders with Flexible Stem,” Simon Fraser University, Canada 2003].
In chest and abdomen minimally invasive surgery, the entry portals for surgical instruments are usually placed some distance apart, and the instruments approach the operative site from somewhat differing directions. This arrangement makes it possible (though sometimes inconvenient and limiting) for telesurgical systems, such as the DaVinci or Zeus, to use rather large robotic slave manipulators for extracorporeal instrument positioning. The optimal placement of entry portals based on dexterity requirements for particular procedures is an important subject and has recently been addressed by several authors [L. Adhami and E. C. Maniere, “Optimal Planning for Minimally Invasive Surgical Robots,” IEEE Transactions on Robotics and Automation, vol. 19, pp. 854-863, 2003; J. W. Cannon, J. A. Stoll, S. D. Sehla, P. E. Dupont, R. D. Howe, and D. F. Torchina, “Port Placement Planning in Robot-Assisted Coronary Artery Bypass,” IEEE transactions on Robotics and Automation, vol. 19, pp. 912-917, 2003]. In contrast, with minimally invasive surgery of the throat, the size and location of the entry port is pre-determined and no such optimization is possible.
The upper airway of the throat is a long, narrow, and irregularly shaped organ that includes the pharynx (throat), hypopharynx, and larynx, commonly referred to as the voice box. These areas are subject to a variety of benign and malignant growths, paralysis, and scar tissue formation requiring surgical interventions for excision and/or reconstruction. These procedures also often must be performed past the vocal cords closer to the lungs. In order to maintain the voice characteristics, it is very important to be able to reconstruct the vocal cord region as accurately as possible. These procedures (e.g., partial or total laryngectomy, vocal fold repositioning, and laryngotracheal reconstruction) are routinely performed using open surgical techniques at the expense of damaging the integrity of the framework supporting the laryngeal cartilage, muscle, and the connective tissue vital to normal function. A minimally invasive endoscopic procedure is generally preferred over the open procedure, as it would preserve the laryngeal framework integrity, promote faster recovery and frequently overcome the need for tracheostomy.
There is shown in FIGS. 1A, B a conventional minimally invasive system that is used for the performance of laryngeal surgery. As illustrated, the internal regions of the airway are accessed through the use of an array of long instruments (usually ranging between 240 to 350 mm long) through a laryngoscope that is inserted into the patient's mouth and serves as a visualization tool and a guide for surgical instrumentation. The laryngoscope is typically 180 mm long with an oval cross-section usually ranging between 16-20 mm in width at its smallest cross section.
This surgical setup involves the surgeon manipulating several long tools, instruments or devices (for example, one tool for suction and another for tissue manipulation). The conventional instruments or devices, as indicated herein, are constrained by design to provided four (4) degrees of freedom of motion (or less) and also are characterized as lacking tool-tip dexterity. Consequently, such instruments or devices do not provide the surgeon with the required tip dexterity to allow the user to perform delicate and accurate surgical procedures such as for example, soft tissue reconstruction and sewing. Further, the vocal folds preclude the performance of surgical procedures past them using such instruments or devices.
Consequently, and due to these limitations, laryngeal minimally invasive surgery is currently limited to simple operations such as microflap elevation, excisional biopsies, and removal of papilloma using laser or powered microdebrider. Functional reconstructive procedures (e.g., tissue flap rotation or suturing), are not performed in throat minimally invasive surgery, although, reconstruction of the vocal fold structures as accurately as possible is crucial for maintaining the voice characteristics. Suture closure of surgical defects has been shown to reduce scar tissue, shorten healing time, and result in improved laryngeal function and sound production (D. J. Fleming, S. McGuff, and C. B. Simpson, “Comparison of Microflap Healing Outcomes with Traditional and Microsuturing Techniques: Initial Results in a Canine Model,” Ann Otol Rhinol Laryngol., vol. 110, pp. 707-712, 2001; P. Woo, J. Casper, B. Griffin, R. Colton, and C. Brewer, “Endoscopic Microsuture Repair of Vocal Fold Defects,” J. Voice, vol. 9, pp. 332-339, 1995). This seemingly simple operation is very difficult, if not impossible, to perform in laryngeal minimally invasive surgery.
Although laryngeal surgery is exemplary, many other minimally-invasive surgical procedures have similar needs for precise, high dexterity motions in confined spaces within a patient's body. Further, it is often necessary to operate multiple instruments in close proximity to each other, where the instruments are inserted into the body through roughly parallel access paths in confined spaces such as the throat. Further, the physical size of the instruments is often a significant factor in determining the feasibility of procedures. Further, as instruments are constructed to be smaller-and-smaller, designs using conventional approaches involving complicated linkages become more and more difficult and costly to fabricate and are increasingly susceptible to limitations due to backlash and other factors.
It thus would be desirable to provide improved methods and devices for minimally invasive surgeries. It also would be desirable to provide new devices and systems particular suited and adaptable for use with a wide range of minimally invasive surgical techniques that provide a similar freedom of motion at the treatment site as would be experienced using open surgical procedures or techniques. It also would be desirable to provided such minimally invasive devices and systems that provide such motion in a constrained surgical environment such as that presented in the throat and sinus. It also would be desirable to provide methods for treating any of a number of organs or areas of a body, more specifically the throat and sinus, using such devices and systems. It would be desirable to provide methods and devices that are capable of performing surgery on particularly challenging sites such as the throat. It would be highly desirable to provide methods and devices that are configurable to operate at multiple physical scales, ranging from small to extremely small, without requiring fundamental changes in the design concept approach. Such methods and devices should overcome the deficiencies of the presently available methods and devices.